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Session 75 - The Crab Nebula.
Display session, Thursday, June 13
Great Hall,

[75.04] The Polarization and Spectra Indices of The Inner Crab Synchrotron Nebula at WFPC2 Resolution

A. M. Watson (NMSU), J. J. Hester, H. Van Tassel, P. A. Scowen, R. Sankrit (Arizona State U.), F. C. Michel (Rice U.), J. R. Graham (UC, Berkeley), J. S. Gallagher (U. Wisconsin, Madison)

We have obtained unique observations of the inner arcmin of the Crab synchrotron nebula with WFPC2. We present polarization and spectral index images from a single epoch. These data provide essential astrophysical information on the bright features in the inner nebula, including K1, the polar emission feature discovered by Hester et al. (1995), and the anvil, the region behind the shock from the polar relativistic wind. By isolating features and subtracting off the background in each of the three polarization frames we isolate the polarization of sharp features in the inner nebula. The magnetic field is seen to lie along the length of the wisps and striations in the nebula. The knot K1, located approximately 0.6 arcsec to the SE of the pulsar, is observed to be somewhat redder than the rest of the nebula, and is polarized with the magnetic field running perpendicular to the spin axis of the system. This is consistent with the helical magnetic field expected in the pulsar wind at high latitude. The knot K2, interpreted in an accompanying paper as the shock in a polar jet, is seen to have relatively low polarization, with again with a net magnetic field perpendicular to the spin axis of the system.

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